At the top of the game when it comes to fast fashion, Inditex – the group that owns Zara – is just as swift with its thinking. Its expansion into international markets is serious, with more than a third of its sales this year coming from China and the US, up 29% from a year earlier. Online now accounts for an increasing amount of sales, with 1.3 million people visiting the site every day. Zara's USP is a high turnover of stock that is fashion-aware but never too out there, priced affordably but not cheap as chips. It's a formula that has contributed to Inditex's recent 17% rise in sales figures.

A sleepy high-street brand until Jane Shepherdson took over in 2008, bringing with her a grown-up, minimal-but-feminine aesthetic. Several pieces – the pleated Carrie skirt, the Wren pink suit – became cult items. Well on the radar of industry insiders, Whistles under Shepherdson has – crucially – never been too high-fashion for regular folk. This balance has helped financially, with sales growing 11% in 2011 and strong this year. Part-owned by the Icelandic government since bank Glitnir went bankrupt in 2008, the majority of shares were bought back last month. Expansion is now on the cards.

The grand dame of the British high street has played its traditionalism to its advantage, post the financial crisis. The official department store of the Olympics (the middle classes loved the themed carrier bags in signature 2012 colours), John Lewis also benefited from the Diamond Jubilee – sales in the first half of this year almost trebled. It was also a masterstroke to collaborate with London fashion week designer Alice Temperley on the Somerset range. Her very English romanticism is on message for John Lewis – so much so that it became the fastest selling brand launch in the store's history, hitting weekly sales targets in an afternoon.

It seems there is no stopping this internet fashion powerhouse. Launched in 2000, with the acronym of As Seen on Screen, and a focus on celebrities' clothes, it is now bookmarked by millions. Reporting a 31% rise in sales this week, these latest figures have been attributed to growth in Australia and the US, two more territories now familiar with the website's fast turnover of cool, cleverly priced merchandise. A mix of entry-level designer brands, high street and their own label, its success is perhaps down to a something-for-everyone attitude. Asos's output runs from collaborations with designers (Markus Lupfer is next) to a pair of standard A to B flats for under £20.

The second largest fashion retailer – only Inditex, which owns Zara, is bigger – saw profits grow 7% in the third quarter. It has stayed at the top by covering all bases. H&M is a place where you can buy a T-shirt for a fiver, or a piece of designer history. The store, and, in particular, creative adviser Margareta van den Bosch, pioneered the high-street/designer collaborations, which often resulted in queues around the block (this year's Versace range was particularly frenzied). Its latest hook-up with Vogue editor and blogger Anna Dello Russo.

In the doldrums recently, the future looks bright for Gap. Reporting its first growth in sales in seven months this February, the brand is going back to basics. Pieces going into store for winter have the American preppy-meets-sporty style that the brand does so well – with reworked favourites such as the waffleknit sweater and fur-trimmed parka, as well as the trademark 1969 jeans now in skinny bootcut and boyfriend shapes. It's about to get even better. Rebekka Bay (who gave us Cos) becomes creative director next month. It will be exciting to watch her strip things down and take this American classic back to its former glory.

Teetering on the edge of bankruptcy in 2010, hipster favourite American Apparel has fought back by tightening up what it does. Known as an easy place to shoplift – a novella was even dedicated to it in 2009 – the chain has introduced a new security system to stop employees helping themselves to the stock and seen activity drop up to 75%. The demand for its slightly retro aesthetic, beefed up with cotton basics, is still there too. Sales were up 24% in August so we might be spared a nation of naked hipsters just yet.

Reporting a 6.8% drop in sales across the non-food business in July, M&S, once a stalwart of British high street fashion, saw its share of the female clothing market go from 10.9% to 10.5% from 2011 to 2012. It might not sound like much but that's about a £100m loss in sales. What's the problem? M&S seems a bit out of touch with what women want out of their shopping experience. Shopfloors are cramped with clothes, and navigating the stores can be a nightmare. All may not be lost, though. New style director Belinda Earl (formerly of Jaeger) started this month, while a lingerie collaboration with model Rosie Huntington-Whiteley was its fastest-selling underwear collection ever.

Marking its 40th anniversary this year, French Connection's problems could be likened to a brand entering middle-age. With a loss of £6.3m in the first half of the year, a two-year turnaround plan was announced this week. They could do worse than look to competitors such as Cos and Whistles who have targeted a sophisticated, grown-up customer. Right now, French Connection seems unsure – just look at its ad campaigns. FCUK campaign worked well for a cheeky 1990s consumer but new, almost philosophical tone – "This is the collection" – jars with stock that focuses on workwear and partydresses. Lower prices and a more cohesive ad-to-store identity would certainly help.

Shoppers are tired of the brand … Superdry. Photograph: Martin Godwin for the Guardian

its appeal might be a mystery to the fashion industry, but Superdry's distressed hoodies and logo-heavy retro T-shirts have taken it far. The first store opened in 2004, and it became one of the fastest-growing fashion brands in the world by 2010. Its designs are ubiquitous on high streets everywhere – although, some will be pleased to hear, the general populace may have tired of the brand. Superdry's parent company, Supergroup, announced a 15% drop in profits from 2011 to 2012, while one of the founders, Theo Karpathios, left unexpectedly in August. Things might no be so super any more.